Acids, Bases and Salts — Practice

Question 1

What colour does red litmus turn in a base?

Accepted Answer

Red litmus turns blue in a base.

Question 2

Name the natural indicator obtained from lichens.

Accepted Answer

Litmus.

Question 3

What is neutralisation? Write a general equation with an example.

Accepted Answer

Neutralisation is the reaction of an acid with a base to form salt and water. Acid + Base = Salt + Water, e.g. HCl + NaOH = NaCl + H2O.

Question 4

Why is lime added to acidic soil?

Accepted Answer

Lime (calcium hydroxide) is basic. It neutralises the excess acid in the soil, making it suitable for plant growth.

Question 5

Differentiate between the treatment of a bee sting and a wasp sting.

Accepted Answer

A bee sting injects formic acid, so it is treated with baking soda (a base). A wasp sting is basic, so it is treated with vinegar (a mild acid).

Practice — Acids, Bases and Salts